! Importance of Particle Adhesion ! Importance of Particle Adhesion - PowerPoint PPT Presentation

! Importance of Particle Adhesion ! Importance of Particle Adhesion ! History of Particle Adhesion ! History of Particle Adhesion ! Method of measurement of Adhesion ! Method of measurement of Adhesion ! Adhesion Induced Deformation ! Adhesion Induced Deformation ! JKR and non ! JKR and non- -JKR Theory JKR Theory ! Role of Electrostatic Forces ! Role of Electrostatic Forces ! Conclusions ! Conclusions ME 437/537 G. Ahmadi ME 437/537 G. Ahmadi Articles Books: H. Krupp, Advan. Colloid Interface Sci. 1, 111 (1967). D. S. Rimai and D. J. Quesnel, Fundamentals of Particle Adhesion , Global Press (available K. L. Johnson, K. Kendall, and A. D. Roberts, Proc. R. Soc. London, Ser A 324, 301 (1971). through the Adhesion Society at adhesion society.org) (2001). D. S. Rimai and L. P. DeMejo, Annu. Rev. Mater. Sci.26, 21 (1996). D. J. Quesnel, D. S. Rimai, and L. H. Sharpe, Particle Adhesion: Applications and Advances , Taylor and Francis (2001) D. S. Rimai and A. A. Busnaina, Particulate Science and Technology 13, 249 (1995). B. Gady, D. Schleef, R. Reifenberger, D. S. Rimai, and L. P. DeMejo, Phys. Rev. B 53, 8065 (1996). D. S. Rimai and L. H. Sharpe, Advances in Particle Adhesion , Gordon and Breach Publishers (1996). N. S. Goel and P. R. Spencer, Polym. Sci. Technol. 9B, 763 (1975). D. S. Rimai, L. P. DeMejo, and K. L. Mittal, Fundamentals of Adhesion and Interfaces , VSP D. Maugis and H. M. Pollock, Acta Metall. 32, 1323 (1984). Press (1995). L. N. Rogers and J. Reed, J. Phys. D 17, 677 (1984). K. L. Mittal, Particles on Surfaces: Detection, Adhesion, and Removal, 1 , 2 and 3, Plenum K. L. Johnson, K. Kendall, and A. D. Roberts, Proc. R. Soc. London Ser. A 324, 301 (1971). Press (1986), (1988), (1990), (1995). B. V. Derjaguin, V. M. Muller, and Yu. P. Toporov, J. Colloid Interface Sci. 53, 314 (1975). A. Zimon, Adhesion of Dust and Powders , Consultants Bureau (1976). D. Tabor, J. Colloid Interface Sci. 58, 2 (1977). T. B. Jones, Electromechanics of Particles , Cambridge University Press (1995). V. M. Muller, V. S. Yushchenko, and B. V. Derjaguin, J. Colloid Interface Sci. 77, 91 (1980). J. Israelachvili, Intermolecular and Surface Forces , Academic Press (1992). D. J. Quesnel, D. S. Rimai, and L. P. DeMejo, J. Adhesion 51, 49 (1995). ME 437/537 G. Ahmadi ME 437/537 G. Ahmadi 1

Articles Technologically important Technologically important Soltani, M. and Ahmadi, G., On Particle Adhesion and Removal Mechanisms in Turbulent Flows, J. Adhesion Science Technology, J. Adhesion Science Technology Vol. 7, 763-785 (1994). A. Semiconductor fabrication A. Semiconductor fabrication Soltani, M. and Ahmadi, G., On Particle Removal Mechanisms Under Base Acceleration, J. Adhesion Vol. 44, 161-175 (1994). B. Electrophotography B. Electrophotography Soltani, M., Ahmadi, G., Bayer, R.G. and Gaynes, M.A., Particle Detachment Mechanisms from Rough Surfaces Under Base Acceleration, J. Adhesion Science Technology Vol. 9, C. Pharmaceuticals C. Pharmaceuticals 453-473 (1995). Soltani, M. and Ahmadi, G., Direct Numerical Simulation of Particle Entrainment in D. Paint D. Paint Turbulent Channel Flow, Physics Fluid A Vol. 7 647-657(1995). Soltani, M. and Ahmadi, G., Particle Detachment from Rough Surfaces in Turbulent Flows, E. Agriculture E. Agriculture J. Adhesion Vol. 51, 87-103 (1995). Soltani, M. and Ahmadi, G., Detachment of Rough Particles with Electrostatic Attraction F. Aeronautics and space F. Aeronautics and space From Surfaces in Turbulent Flows, J. Adhesion Sci. Technol., Vol. 13, pp. 325-355 (1999). Soltani, M., Ahmadi, G. and Hart, S. C., Electrostatic Effects on Resuspension of Rigid-Link G. Etc. G. Etc. Fibers in Turbulent Flows, Colloids Surfaces, Vol. 165, pp. 189-208 (2000). ME 437/537 G. Ahmadi ME 437/537 G. Ahmadi � Particles are attracted to substrates (or � Particles are attracted to substrates (or Fundamentally Important Fundamentally Important other particles) via certain types of other particles) via certain types of A. Avoids confounding interactions A. Avoids confounding interactions interactions. These interactions create interactions. These interactions create (gravity, applied loads, etc.) (gravity, applied loads, etc.) stresses between the materials. These stresses between the materials. These stresses, in turn, create strains that may stresses, in turn, create strains that may be be B. Allows thermodynamic parameters such B. Allows thermodynamic parameters such large or small, elastic or plastic. large or small, elastic or plastic. as work of adhesion to be determined. as work of adhesion to be determined. � Only by understanding both the � Only by understanding both the interactions interactions C. Allows present understanding of C. Allows present understanding of and the mechanical and the mechanical response of the response of the adhesion to be tested. adhesion to be tested. materials to these interactions can adhesion interactions can adhesion materials to these be understood. be understood. ME 437/537 G. Ahmadi ME 437/537 G. Ahmadi 2

� Hertz (circa 1890): Proposed that a rigid indenter, � � This presentation will focus on particle � Hertz (circa 1890): Proposed that a rigid indenter, This presentation will focus on particle acting under a compressive load P, would cause a acting under a compressive load P, would cause a adhesion. However, just as the JKR adhesion. However, just as the JKR deformation of radius a a in a substrate having a in a substrate having a deformation of radius theory describes adhesion between theory describes adhesion between ν given by and a Poisson ratio ν Young’ ’s modulus s modulus E E and a Poisson ratio given by Young ( ) macroscopic bodies, the concepts presented presented macroscopic bodies, the concepts − ν 2 3 1 RP = can be readily generalized to other can be readily generalized to other 3 a 4 E situations. situations. � 1930s: � 1930s: Derjaguin Derjaguin and Bradley independently and Bradley independently proposed proposed � The JKR model is the underlying theory on � The JKR model is the underlying theory on the concept of adhesion- -induced induced deformations between deformations between the concept of adhesion which most of our present understanding of which most of our present understanding of particles and substrates. particles and substrates. Derjaguin Derjaguin assumed that the assumed that the adhesion is based. adhesion is based. adhesion- adhesion -induced contact radius can be calculated induced contact radius can be calculated from from Hertzian Hertzian theory. theory. ME 437/537 G. Ahmadi ME 437/537 G. Ahmadi � 1937: Hamaker proposes that surface forces � 1937: Hamaker proposes that surface forces � By combining this result with the � By combining this result with the Hertzian Hertzian were related to the density of atoms in the were related to the density of atoms in the indenter model, one sees that the Derjaguin Derjaguin indenter model, one sees that the particle and substrate, n n P and n n S , respectively. particle and substrate, P and S , respectively. model relates the contact radius to the model relates the contact radius to the Hamaker further proposed that the interaction Hamaker further proposed that the interaction particle radius by particle radius by A (commonly referred to as the parameter A parameter (commonly referred to as the Hamaker constant) was related to London Hamaker constant) was related to London ( ) dispersion forces by dispersion forces by = π λ 2 A n n − ν 2 P S A 1 = 3 2 a R 2 The load P P is then given by is then given by The load A R 8 z P = 0 2 6 z 0 ME 437/537 G. Ahmadi ME 437/537 G. Ahmadi 3